#include <string>

using namespace std;

class StringUtils
{
public:
	static bool isEmpty(const string& str) {
		
		return str.empty();
	}


	static string UtfToGbk(const char* utf8)
	{

		int len = MultiByteToWideChar(CP_UTF8, 0, utf8, -1, NULL, 0);

		wchar_t* wstr = new wchar_t[len + 1];

		memset(wstr, 0, len + 1);

		MultiByteToWideChar(CP_UTF8, 0, utf8, -1, wstr, len);

		len = WideCharToMultiByte(CP_ACP, 0, wstr, -1, NULL, 0, NULL, NULL);

		char* str = new char[len + 1];

		memset(str, 0, len + 1);

		WideCharToMultiByte(CP_ACP, 0, wstr, -1, str, len, NULL, NULL);

		if (wstr) delete[] wstr;

		return str;

	}




};